Automatic sanding machine



June 26, 1928.

1,675,183 w. LoEFFLr-:R

AUTOMATIC SANDING MACHINE Filed July 2s, 1925 5 sheets-sheet 1 June 26, 1928. 1,675,183

w. LOEFFLER AUTOMATIC SANDING MACHINE Filed July 25, 1925 5 sheets-sheet 2 June 26, 1928. 1,675,183

w. LOEFFLER AUTOMATIC SANDING MACHINE Wm. Lneffl Er `lune 26, 1928.

W. LOEFFLER AUTOMATIC SANDING MACHINE Filed July 23, 1925 5 Sheets-Sheet 4 June 26, 1928. 1,675,183

W. LOEFFLER AUTOMATIC SANDING MACHINE Filed July 2:5, v1925 5 sheets-sheet 5 GJ//w/f/o/i/f Wm- Lneffler "yg/W4 raiatd alla.. 2:6, ieee.

UNITED STATES WILLIAM LOEFFLER, OF SHEBOYGAN, WISCONSIN.

AUTOMATIC SANDING MACHINE.

Application led July 23,

This invention relates Yto automatic sanding machines. I

Objects of this inventlon are .to provide a machine which will sand toilet seats or similar work, which will sand over the curved transverse bulge or round portlon of the scat, which will take' off the ribs left by the rough cut resulting from the orlglnal production of the seat, and which 1s automatic throughout..

Further objects are to provide an automatic sanding machine which will start when the work is presented, which will accurately sand completely around the seat, which is timed and will automatically stop when the Work is completed, and to provide means for timing the machine which may be varied throughout a wide range.

Further objects are to provide a seat sanding machine 1n which the traveling sanding belt is automatically oscillated up and down on opposite sides of a section of the seat, in which the carriers or belt guiding members are independently oscillated, in which means are provided for independently adjusting such carriers, and in which means are provided for varying the rate of osclllation to accommodate different types of work.

Further objects are to provide a sanding machine which will automatically grip the work as the work is driven after the completion of a cycle of operations, which will automatically release the work, which will remove the work from the sanding belt when the operation is complete, and which will automatically stop and reset the timing mechanism.

An embodiment of the invention is shown in the accompanying drawings, in which Figure 1 is a front elevation of the machine.

Figure 2 is a side view of the structure shown in Figure 1 with parts in section.

Figure 3 is a sectional view approximately on the line 3-3 of Figure 1.

Figure 4 is a detail of the work holding mechanism with the work removed.

Figure 5 is a view from the under side of the work engaging ring.

Figure 6 is a view of a portion of the work support into which the ring fits.

Figure 7 is a sectional View on the line 7-7 of Figure 1.

Figure 8 is a fragmentary detail of the 19.25. Serial No. 45,629.

timing mechanism looking from the rear side of the machine. j

Figure 9 is a view corresponding to Figure 8 looking from the front side.

Figure 10 is a sectional view through a portion of the timing mechanism, such view corresponding to Figure 8.

Figure -11 is a fragmentary detail showing the cam drivingr mechanism which controls the oscillating belt carriers.

Figure 12 is an enlarged View of the lower end of the oscillating belt carrying mechamsm.

Figure 13 is a sectional view on the line 13-13 of Figure 11.

Figure 14 is a face view of the cams with the rest of the apparatus removed.

The machine comprises an upright frame i structure which carries at its upper end the main driving shaft 1. Thls shaft is equipped with tight and loose pulleys 2 at one end` and with a small drivlng pulley 3 adjacent such end. The other end of the driving shaft 1 carries the driving wheel 4 for the sanding belt 5. This driving wheel or drum may be relatively large to impart thc requisite speed to the belt. An arm 6 is pivotally mounted (zo-axially of the shaft 1 and may be carried either directly by the shaft or by an extension of the front bearing 7 (see Figure 2). The lower end of this arm 6 is provided with a pair of transverse shafts 8 and 9 upon which short arms 1() and 11 are mounted, such arms being illustratcd in greater detail in Figure 12. The arms 10 and 11 carry rollers or pulleys 12 and 13 upon which the sanding belt 5 travels. These rollers or carriers for the belt are oscillated by rocking the shafts 8 and 9, and consequently the sanding belt 5 is caused to partially wrap about and rock about the seat A. thus conforming to the transverse curvature of the seat and removing all of the sharp corners thereof.

In order to hold the belt down against the seat and remove the abrupt corners usually found in seats. as shown in Figurev12, a bearing foot 14 is provided and is carried by a plunger 15. such plunger being slidably mounted in a sleeve 16 and urged downwardly by means of a spring 17. The plunger is preferably provided with a pair of nuts at its upper end to prevent its complete retraction from the sleeve 16. An adjustment of the pressure exerted by the foot 14 may be had by means of the slot and screw mechanism illustrated at 18, the slots being formed in an integral ear 19 of the sleeve 16 and the screws passin through into the arm 11. Thus for har and soft wood, the adjustment of this portion of the mechanism may be most easily changed to adapt the machine to the particular grade of material operated upon.

The means for rocking the shafts 8 and 9 may comprise a pair of crank arms 20 and 21 (see Figures 1 and 3). These crank arms are equipped with links 22 and 23 which extend upwardly and carry rollers 24 at their upper ends (see Fig. 2). Also these rollers, or else the axles therefor, are guided in slots formed in a guide 25, as shown most clearly in Figure 2, to cause the rollers to travel vertically upwardly andvdownwardly when actuated by the cams hereinafter described.

A short shaft 26 is mounted transversely of the machine, as shown in Figure 2, and carries a sleeve 26 rigid with theeams 27 and 28, such cams being provided with grooves within which the rollers 24 are received. T he sleeve is-driven through bevel gearing from the shaft 29. This shaft l29 is square at its outer end, as shown in Figures 2 and 11 and slidably passes through a gear 30, such gear` being carried within a housing 31. The gear 30 meshes with a gear 32 which is rigid y secured to a shaft 33. YThis shaft 33 is provided with a beveled gear 34 which meshes with a beveled ear 35 carried by a transverse shaft 36. It 1s to be noted that the housing 31 is provided l with a pair of arms 37 which are pivotall mount-ed upon the transverse shaft 36. This transverse shaft 36 is a, variable speed shaft and is provided with a large gear 38 and with a smaller gear 39 through either of which it is driven.

The gears 38 and 39 are adapted to mesh with the gear 40 or the gear 41 see Figure 2) such gears being slidably sp ined upon a transversely driven shaft 42. The shaft 42 carries a gear 43, as shown in Figure 2, which is loose thereon and is adapted to be locked to such shaft b means of the clutch 44. The ear 43 mes es with a small gear 44 carrie by a short shaft 45 (see Fig. 3). The short shaft 45 is provided with a relatively lar e pulley 46 which is belted to the small pulley 3 on the main driving shaft 1, as shown in Figure/2. Thus a reduced speed is transmitted from the shaft 1 to the shaft 36, (see Fi ure 2) such latter shaft carrying the cams 2 and 28. The speed of rotation of these cams may be varied by selectively coupling the gears 40 and 38 or 41 and 39. the gears 40 and 41 being slidablysplined u on the shaft 42, as described and controlle by means of the manually operable lever 47, shown particularly in Figure 3. Thus, as the sanding belt is driven the pulleys 12 and 13 are oscillated by means of the cams 27 and 28 and the belt 1s caused to wrap about the work and conform to the transverse curvature thereof, it being noted that the shoe 14 (see Figure 12) aids in removing the sharp corner usually found in the roughly cut seats.

Mechanism is rovided for oscillating the arm 6 in accor ance with the contour of the seat A. This mechanism is driven from the shaft 42, as will be described herewith. Such shaft is connected by means of bevel gearing with a vertical shaft 48, (see Figure 2) which in turn drives a second vertical shaft 49 by means of sprocket wheels 50 and 51, and a suitable chain. The shaft 49 carries a cam 52 at its upper end (see Figure 3). This cam is provided with a groove within which a roller, carried by the outer end of the sliding arm 53, works. This sliding arm is pivotally joined, as indicated at 54, to a transverse portion of the rocking arm 6. In connection with this rockinr arm 6, it is to be noted 'that a somewhatsimilar arm 6 is provided and is coaxially mounted upon the shaft 1, as shown in Figure 2. These arms are joined by the member 55, shown in Figure 3. Thus the rocking arm is oscillated by means of the cam 52, the cams 27 and 28 rocking back and forth with the rock arm. The shaft 29 (see Figure.; 2 and 11) slides inwardly and outward] through the gear 30, as previously descri ed, to permit this free rocking movement.

It is to be noted that the cam 52 is eontoured so as to move the rocking arm 6 in accordance with the contour of the seat A. This cam may be readily replaced by other cams contoured to fit other types of seats. It is intended, however, that a particular cam needed for a certain type of seat be furnished to the manufacturer of that type of seat.

The mechanism for carrying the seat will now be described. This mechanism comprises a vertically movable shaft 56 slid ably carried in suitable bearings in the frame of the machine, as shown in Figure 2. This shaft is provided with fixed collars 57 between which a loose collar 58 works (see Fi. 2). This loose collar is pivotally att-ache to a lever 59, such lever being connected at one end by means of a link 60 with a stationary portion of the machine and being provided at the other end with a mani ulating handle 61. Thus when the hand e 61 is raised, the shaft 55 is elevated and presents the work to-the sanding belt, as described in greater detail hereinafter.

When the lever 59 is in its lowermost position, the clutch 44 is opened by means of a bar 62 rigidly secured to the lever 59, as shown' in Figure 2. This bar contacts at Iii() its upper end with an adjustable bolt or screw 63 carried in a saddle-like device 64. Such device is in reality a U-shaped strap within which the upper end of the arm 64 operates. It is pivotally carried at the lower end of the clutch lever 65 and is supported by means of a transverse pin 66 passing through the arm 62. When the lever 55 is elevated, the clutch closes, as it is a spring operated clutch, and the cam mechanism and the work rotating mechanism hereinafter described, is set in operation.

The shaft 56 is slidably connected to a sprocket wheel 66 which is connected by means of a suitable chain with a sprocket wheel 67 carried by the vertical shaft 48 (see Figures l, 2 and 7). The sprocket wheel 66, as stated, is loosely splined upon the work rotating shaft 56 so that such shaft may7 be elevated or'lowered withoutinterfering with the action of the sprocket wheel. The upper end of the shaft 55 carries a spider-like member 68 which is provided with an outer ring 69. This ring is provided with a depressed portion 70 within which the work engaging ring 71 is positioned. This work engaging ring` as most clearly shown in Figures 4, 5 and 6, carries a pair of shoes or clamping members 72 which are adapted to grip the seat upon opposite sides, as shown in Figure 3. The shoes 72 are guided in slots 73 formed in the ring 71, as most clearlyl shown in Figure 4, and are provided wit pins 75. These pins project through slots 76 (see Figure 5) formed in the member 71 and through slots 77 formed if. the member 69. The member or ring 71 is provided with a stop 78 against which the flat rear portion of the seat A is adapted to contact, as shown in Figure 3.

The work is positioned between the clamping blocks or jaws 72 when the lever 59 is in its lowest positioneand when the work supporting means is correspondingly lowered. The lever 59 is then elevated by means of the handle 61 thus presenting the seat A to the sanding belt 5 due to the elevation of the shaft 56. The shaft 56 is rotated in the direction of the arrow shown in Figure 3, andthis causes the pins to slide inwardly along the slanting slots 77 due to the frictional drag of the belt upon the seat A. This causes the shoes or jaws 72 to automatically clamp the seat in position and hold it rigidly to the Working supporting means. The working supporting means is locked in elevated position by means of automatie latehing mechanism hereinafter described. However, when the seat has been completely sanded, the latchin mechanism is released and the lever 59, s aft 56, and work supporting means are allowed to drop. Shock, however, is prevented by means of the spring 79 (see Figure 2) one end of which is connected to the lever 59 and the other end of which is carried by an adjustable eye bolt 80 carried by a fixed portion of the machine and held in place by means of an adjusting nut, as illustrated particularly in Figure 2.

The timing mechanism andthe automatic latching mechanism will now be described. This mechanism operates upon the shaft 56 to hold such shaft elevated by means of the link 8l (see Figures 2, 8 and 9). This link 8l has its lower end connected to the lever 59 (as shown in Figure 2) and its upper end connected with a plunger 82 guided in a suitable manner, as shown in Figures 8 and 9.

The plunger 82 is provided with a beveled' upper face 83 and with a notch 84. A latching slide 85 is adapted to enter the notch 84 when the lever 59 is elevated and to thus lock the work supporting means temporarily in elevated position. This slide 85 is carried upon a transverse portion 86 of the machine frame, as shown in Figures 7 to 10, and is secure-d thereto by means of the slot and pin connection illustrated particularly in Figure 7. It is provided with a laterally projecting pin 87 which is connected to a spring 89, the other end of lsuch spring, as shown in Figure 7, being connected to a stationary portion of the machine. A second slide 9() is mounted preferably abovev the slide 85, as shown in Figures 7 to 10, and is provided with an upturned end 91 which contacts with the plunger 82 when such plunger is elevated. The slide is similarly urged inwardly by means of the spring 92, as shown in Figure It is to be noted that the slide 9() rigidly carries a housing 93 within which a worin wheel 94 is mounted. This Worm wheel rigidly carries a worm wheel shaft 95 which projects from opposite sides of the housing. It is adapted to mesh with a worm 96 (see Figure 10) which is mounted upon the shaft 49. This intermeshing occurs when the slide 90 is urged outwardly and occupies the position shown in Figures 8 and. 9. The worm wheel is disconnected from the worm when the plunger 82 is in its lowest position, as shown in Figure 10, and consequently when the slide 90 has moved to its outer position.

It is to be noted from Figures 7 to 10 that the worm wheel shaft 95 is provided with an arm 97 upon one end thereof which contacts with a pin 98 when the worm is in itsinitial position. This pin 98 is adapted to be .placed in any of the apertures 99 in the worm wheel housing 93 (see Figure 8) to thus adjust the initial position of the worm wheel. When the worm wheel is disconnected from the worm, the arm 97 is held in contact with the pin 98 by means of the weight 100. This weight is attached to a cord 101 passing over a suitable pulley and wrapped about a drum 102 rigidly carried by the worm wheel shaft 95, as most clearly shown in Figure 8. 'Ihe other end of the worm wheel shaft is provided with an arm 103 which, in the final position of the worm, is adapted to engage a lug 104 (see Fi ure 9) rigidly carried by the slide 85. T is retracts the slide from engagement with the notch 84 of the plunger 82 and permits the langer to descend, thus lowering the work liolding means. When the plunger descends the iipturnedv end 91 of the slide 90 rides outwardly and thus draws the worm wheel casing 93 rearwardly, tliils disconnecting the worm wheel 94 from tlie worm 96 and permitting the worm to a ain assume its initial position, as shown in igure 8, under the inuence of the weight 100.

From this portion of the mechanism, it is apparent that the length of time during which the sanding belt will operate upon the seat is determined by the setting of the pin 98 in the appropriate one of the apertures 99. Further, it is apparent from this mechanism that the machine is automatically stopped when the sanding is completed.

It is clear from the description heretofore given how the individual portions of the mechanism operate. However, it is believed that a brief rsum of the operation of the machine will aid in a clear understanding thereof.

Starting with the shaft 56 in its lowest position, a seat A is positioned between the clamping jaws 72 (see Figure 3.) Thereafter, the handle 61 (see Figure 2) is raised, tlius raising the work into engagement with the sanding belt. At the same time the clutch 44 is closed through the link mechanism described, and the cams 27 and 28 and the cam 52 are set in operation. The seat is rotated and the belt is worked up and down inside and outside of the seat under the control of the cams 27 and 28 which operate the belt carrier rollers 12 and 13 (see Figures 1 and 12). The arm 6 (see Figure 1) is rocked inwardly and outwardly by means of the cam 52, thus following the contour of the seat with utmost accuracy.

It is to be noted that the work supporting means is held in elevated position by means of the latching mechanism illustrated in Figures 7 to 10, and previously described.

Upon completion of the sanding operation, the arm 103 (see Figure 9) has rocked into engagement with the lug 104 of the latch and thus withdraws such latch and permits the work holding mechanism to descend thus withdrawing the work from the sanding belt and opening the clutch 44 (see Figure'2). At the same time, the timing mechanism is reset as the slide moves inwardly, as shown in Figure 10, and withdraws the worm wheel 94 from engagement with the worm 96.

In view of the fact that the belt carriers or pulleys 12 and 13 are given independent motion by means ofthe cams 27 and 28, it is apparent that mechanism must be provided for maintaining-the tension of the belt 5.

This is readily accomplished by providi'n a belt tightening pulley which is carri lliy means of a spring urged arm 106 (see igure 1).

t will be seen that the utmost accuracy maybe attained in sanding seats and that the machine may be ad'iisted to accommodate hard or soft woo or other material as the timing of the machine may be varied to the exact demands of the work. Further, the cam `52 is contoured to correspond to the particular seat operated upon, and thus the sanding instrumentality accurately follows the contour of the seat.

It will be seen further that the oscillating belt carriers cause the belt to uniformly sand all active portions of the seat and to wrap partly around the transverse bulge or curved contour of the seat.

It will be seen further that the machine is wholly automatic in its operation and does not re uire the services of a skilled mechanic for its manipulation.

Although the invention has been described in considerable detail, it is to be understood that the invention may be variously embodied and is, therefore, to be limited only as claimed, and while considerable emphasis has been put upon the fact that the invention is designed for use in connection with the sanding of toilet seats, it is quito obvious and contemplated to employ 1t on work of various types.

I claim:

1. A sandin machine, for sanding an annular seat of irregular contour mounted to rotate about an axis comprising a driving pulley, a rocking arm mounted coaxially'of said pulley, a-pair of guiding pulleys carried adjacent the lower end of said arm, a sanding belt passing over said pulleys, and means for automatically laterally rocking said arm to cause said belt to follow the contour of said seat as it rotates.

2..A sanding machine for sanding an annular seat of irregular contour mounted to rotate about an axis comprising a driving pulley, a rocking arm mounted coaxially of said pulley, a air of guiding pulleys carried adjacent t e lower end of said arm, a sanding belt passing over said pulleys, means for automatically laterally rocking said arm to cause said belt to follow the contour of said seat as it rotates, and means for oscillating said guiding pulleys to cause said belt to pass transversely over said seat.

3. A machine for sanding a ring-like seat of irregular contour mounted to rotate about an axls comprising a driving pulley, a swin ing arm, a pair of guiding pulleys carried' y the free end of said s win 'ng arm, a sanding belt passing over said riving pullUU iio

ley and said guiding pulleys, means for holding the seat in contact with said belt with one of said iding pulleys located inside of said seat an the other located outside thereof and a cam operativel connected with sald arm for rocking sai arm radially of said seat to follow the contour thereof as the seat rotates, said guiding pulleys causing said belt to partially pass around said seat in a transverse manner.

4. A machine for sanding a ring-like seat of irregular contour mounted to rotate about an axis comprising a driving pulley, a swinging arm, a pair of guiding pulleys carried by the free end of said swinging arm, a sanding belt passing over said driving pulley and said guiding pulleys, means for holding the seat in contact with said belt with one of said guiding pulleys located inside of said seat and the other located outside thereof, a cam operatively connected with said arm for rocking said arm radially of said seat to follow the contour thereof as the seat rotates, said guiding pulleys causing said belt to partially pass around said seat in a transverse manner, and means for oscillating said guiding pulleys up and down.

5. A machine for sanding a ring-like seat of irregular contour mounted to rotate about an axis comprising a driving pulley, an arm pivotally mounted coaxially with said pulley, a pair of levers carried by the outer end of said arm and vpivoted thereon, a guiding pulley carried by each of said levers, a sandin belt passing over said driving pulley an said guiding pulley, a work support for holding said seat in contact with said belt intermediate said guiding pulleys, a cam controlling the position of sald arm and causing said arm to follow the contour of said seat as the seat rotates, cams for oscillating said levers, and variable speed mechanism for driving said last mentioned cams.

6. A machine for sanding ring-like seats comprising a traveling sanding belt, work holding means, means `for rotating said work-holding means, elevating means for raising said work holding means-and placing a seat carried thereby in contact with said belt, latch means for retaining said Work holding means in elevated position, timing mechanism driven from said machine for tripping said latch after a predetermined interval, and .means for disconnecting said timing mechanism and resetting such mechanism when said latch has been tripped.

7 A sanding machine for sanding a ringlike seat comprisin a traveling sanding belt, revoluble an work holdin means, mechanism for elevating said wor holding means tojplace a seat in contact with said belt, means for rotating said work holding means, aclutch controlling the operation of said mechanism and controlled by said elevating means, a Worm driven by said machine, a worm wheel for meshing with said worm and mounted upon a slide, a latch associated with said slide for retaining said Work holding means in elevated position, and for retaining said worm wheel in engagement with said worm, an arm carried by said worm wheel and adapted to engage said latch whereby after a predetermined interval, said arm will disengage said latch and cause the machine to stop and the worm to be disconnected from said worm wheel together with removal of the seat from engagement with said belt.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Wisconsin.

WILLIAM LOEF F LER.

vertically adjustable 

